This study is a phase I/II pediatric ACTG trial of the safety and immunogenicity of live attenuated varicella vaccine in HIV-infected children with minimal immunodeficiency. The purpose is to examine the effects of a live-attenuated varicella vaccine on HIV-infected children. The primary questions to be answered concern the safety of the vaccine, when used within this patient population, and the extent to which these subjects are capable of mounting an immune response to the vaccine. Data from a comparison group of HIV-infected subjects with a history of wild type varicella, will be collected. The data will be used to examine whether the vaccine is capable of evoking immune responses similar to those mounted against the disease itself.